Rotary engine

ABSTRACT

A rotary engine comprising a housing, a rotor mounted within the housing for rotation relative thereto about an axis, the peripheral surface of the rotor and the interior surface of the housing defining therebetween first and second chambers, a piston carried by the rotor and movable generally radially thereof in engagement with the housing interior surface, the piston including an interior chamber therein, a first opening extending from the interior chamber through a first piston wall, a second opening extending from the interior chamber through a second piston wall opposite the first wall, and the engine including first control means for permitting flow from the first chamber through the first opening into the interior chamber and second control means for permitting fluid flow from the interior chamber through the second opening to the second chamber.

United tates atent [191 Baker [4 1 Mar. 12, 1974 1 1 ROTARY ENGINE [76] Inventor: James A. Baker, 3104 Main St.,

Bridgewater, Mass. 02324 [22] Filed: July 10, 1972 [21] Appl. No.: 270,503

[52] US. Cl. 123/8.17, 123/833 [51] Int. Cl. F0210 53/00 [58] Field of Search 123/833, 8.35, 8.27, 8.17

[56] References Cited UNITED STATES PATENTS 3,103,919 9/1963 Drapeau 1. 123/833 3,398,725 8/1968 Null 123/817 X FOREIGN PATENTS OR APPLICATIONS 1,384,755 11/1964 France 123/817 414,412 6/1925 Germany l23/8.17 1,622 9/1911 Great Britain 123/817 Primary Examiner-Carlton R. Croyle Assistant ExaminerMichael Koczo, Jr.

[5 7] ABSTRACT A rotary engine comprising a housing, a rotor mounted within the housing for rotation relative thereto about an axis, the peripheral surface of the rotor and the interior surface of the housing defining therebetween first and second chambers, a piston carried by the rotor andmovable generally radially thereof in engagement with the housing interior surface, the piston including an interior chamber therein, a first opening extending from the interior chamber through a first piston wall, a second opening extending from the interior chamber through a second piston wall opposite the first wall, and the engine including first control means for permitting flow from the first chamber through the first opening into the interior chamber and second control means for permitting fluid flow from the interior chamber through the second opening to the second chamber.

18 Claims, 5 Drawing Figures ROTARY ENGINE This invention relates to rotary motors.

It isa principal object of the present invention to provide a smooth-running rotary internal combustion engine in which output forces are applied perpendicular to the output shaft and in which the need for gears and major reciprocating mechanisms is eliminated. Other objects include providing a high efficiency engine of simple construction and having a high horsepower to weight ratio in which, although timing is not critical, undesirable emission by-products are substantially reduced.

The invention features a rotary engine comprising a housing, a rotor mounted within the housing for rotation relative thereto about an axis, the peripheral surface of the rotor and the interior surface of the housing the outer end of each of bearings 20 in engagement defining therebetween first and second chambers, a piston carried by the rotor movable generally radially thereof in engagement with the housing interior surface, the piston including an interior chamber therein, a first opening extending from the interior chamber through a first piston wall, a second opening extending from the interior chamber through a second piston wall opposite the first wall, and the engine including first control means for permitting fluid flow from the first chamber through the first opening to the interior chamher, and second control means for permitting fluid flow from the interior chamber through the second opening to the second chamber. In preferred embodiments in which the rotor carries two identical and diametrically opposite pistons, there is featured a flexible reed overlying the first opening in each piston, a movable closure for controlling flow through the second opening, a retainer for holding the closure fixed with respect to the rotor during one portion of the relative rotation and permitting movement of the closure with the associated piston during another portion of the relative rotation, and a housing interior surface including two surface portions, each surface portion being defined by a portion of a cylinder having an axis parallel to the axis of relative rotation, the two cylindrical axes being offset on opposite sides of the axis of relative rotation, and the two cylinders being of different diameters.

Other objects, features, and advantages will appear from the following detailed description of a preferred embodiment of the invention, taken together with the attached drawings, in which:

FIG. 1 is a sectional, partially diagrammatic, view of a rotary motor embodying the present invention;

FIGS. 2 and 3 are perspective views, partially in section, of portions of the motor of FIG. 1;

FIG. 4'is a sectional view taken generally along 4-4 of FIG. 1; and

FIG. 5 is an exploded perspective view, partially in section, of the piston assembly of the motor of FIG. 1.

Referring more particularly to the drawings, there is shown a rotary internal combustion engine, generally designated 10, comprising an output shaft 12 extending through a multipart housing 13 including a housing center section 14 and a pair of substantially identical housing end plates l6, 18 mounted on opposite sides of center section 14.

Shaft 12 is mounted for rotation relative to the housing by a pair of bearings 20 mounted, respectively, in each of end plates 16, 18. An oil seal 22 is mounted at with shaft 12 and the respective end plate 16, 18.

A cylindrical rotor assembly 24 comprising a rotor center section 26 sandwiched between a pair of end plates 28, 30 is mounted within the annular cavity de fined by housing center section 14 and end plates 16, 18 and is connected to shaft 12 by a keyway 32. Rotor assembly 24 includes two radially-opposite bores 34 of rectangular cross-section. Each bore 34 extends the full width of center section 26, and radially inwardly from the outer cylindrical periphery 36 of center section 26. A piston assembly, generally designated 38, is mounted in each of bores 34 for movement within the bore.

Referring more particularly to FIGS. 3 and 4, each of rotor end plates 28, 30 includes an outwardly projecting annular boss 40 surrounding shaft 12. A pair of drilled holes 42, one associated with each of bores 34 and positioned between the respective bore 34 and shaft 12, extend through rotor assembly 24 parallel to the axis thereof. As shown, each hole 42 lies partially within and partially without boss 40. An annular oiler recess 44 is provided in the outer face of each boss 40 surrounding shaft 12 and radial recesses 46 extend from recess 44 to each of holes 42. An elongated slot 48 extends from the base of each bore 34, parallel to the sides of the bore, through the associated hole 42 to a point inwardly of the hole.

Housing center section 14 includes a pair of inwardly-projecting annular flanges 50 disposed on opposite sides of an inwardly-facing piston engagement surface 52. Each flange 50 has a width equal to that of a rotor end plate 28, 30, and its inner peripheral surface is coaxial with and of diameter equal to that of rotor 24. The peripheral surface of each rotor end plate 28, 30 is sealed to flanges 50 during rotation by segmental sealing rings 56 inset in recesses 54 in the margins of flanges 50 with their sealing surfaces contacting the peripheral surface of the respective end plate. As shown, each flange 50includes two recesses 54, each subtending an arc of about and two sealing rings 56 are held in place in each recess 54 by housing end plates 16, 18.

As shown most clearly in FIG. 1, piston engagement surface 52 has a width equal to that of rotor center section 14 and comprises a pair of partial-cylindrical surface portions 58, 60. The axes 59, 61 of the respective cylinders defining surface portions 58, 60 extend parallel to the axis of shaft 12 but are offset on opposite sides thereof. The radius of the cylinder defining surface portion 58 is less than that of the cylinder defining surface portion 60.-Surface portion 58 subtends an arc of approximately l60; surface portion 60 an arc of approximately 200. The surface portions meet along two spaced parallel seals, designated 57a and 57b, each extending between housing end plates 16, 18 parallel to the axis of shaft 12. Each seal is mounted in a respective recess 55a, 55b with its inner surface at a distance from the shaft axis equal to the radius of rotor 14. The counterclockwise (viewed in FIG. 1) end of each seal is held by a pin 59. The other end is biased inwardly by a leaf spring 61.

Housing surface portion 58 and the underlying portion of peripheral surface of rotor 24 define an intake and compression chamber 62; a combustion and exhaust chamber 64 is defined by housing surface portion 60 the portion of the rotor peripheral surface adjacent thereto. The volume of exhaust and combustion chamber 64 is between 1% and 2 times that of chamber 62.

An inlet conduit 63 and an exhaust conduit 65 extend, respectively, from chambers 62, 64 outwardly through the radial thickness of housing center section 14. A manifold 66 is secured to the outer surface of center section 14 by studs 68 for permitting an air-fuel mixture to flow from carburetor 70 into chambers 62 and to exhaust combustion products from chamber 64 through exhaust conduit 65. A spark plug 72 extends through a threaded hole 73 in housing center section 14, communicating with chamber 64 closely adjacent seal 57b.

An annular groove 74, 76 is provided in the inner face of, respectively, each of housing end plates 16, 18. Each groove includes a fairing portion at the opposite ends thereof, is coaxial with shaft 12, and has a center line coinciding with the circle traced by the axes of each of holes 42 during relative rotation of rotor 24 within housing 13. Groove 74 is radially aligned with surface portion 58 and subtends an are slightly greater than that subtended by surface portion 58; groove 76, aligned with surface portion 60, subtends an are slightly greater than that of surface portion 60.

Referring now to FIGS. 1, 4 and 5, each piston assembly 38 comprises a hollow piston 77 of rectangular crosssection slightly smaller than that of bores 34 and closed at its top 78. A u-shaped seal 82 is mounted in a recess 80 extending across the top and down the side walls of each piston 77 and provides a sliding seal between the piston and the inner surfaces 58, 60 of housing center section 14 during rotation of the rotor. A second sliding seal, between each piston 77 and the walls of the corresponding bore 34, is provided by a mating pair of L-shaped seals 88, 88 mounted in recess 86 extending around the walls of the piston.

A piston block 94 is fitted within the lower portion of each piston 77 and defines, in conjunction with the adjacent interior surfaces of piston 77, an internal piston chamber 96 having a volume of about one-tenth that of intake and compression chamber 62. Three drilled openings 98 extend through the leading wall 90 of piston 77 to chamber 96; a rectangular opening 100 extends from the chamber through the piston trailing wall 92. A flexible reed 102 and reed backing plate 104 are mounted within piston 77 with the base of each of reed 102 and plate 104 secured between block 94 and leading wall 90. As shown, reed 102 includes three fingers 106 extending upwardly from its base. Each finger 106 overlies one of openings 98 and serves to seal the opening against passage of gas from the chamber 96 outwardly through the opening while permitting flow in the reverse direction. Backing plate 104 includes three similar fingers 108, each of which curves upwardly from the backing plate base inwardly away from leading wall 90 into chamber 96 and serves to limit the flexing of one of reed fingers 106.

A piston gate 110 is mounted between piston block 94 and piston trailing wall 92 for sliding movement (in a direction generally radially of rotor 24) between an outer position in which the gate overlies and closes opening 100 and an inner position in which the upper edge 112 of the gate is below (radially of the rotor inwardly from) opening 100. Gate 110 includes a gener ally J shaped leg portion 114 extending through a slot in the lower portion of piston block 94 into the respective slot 48 in rotor center section 26.

A control pin 118 having an axial slot 120 extending generally diametrically therethrough, is slideably mounted in each of holes 42. The ends 119 of pin 118 are rounded, being defined by portions of cylinders whose axes are parallel to each other and form an angle of about 12 with slot 120. A leg portion 114 of one of gates extends through each of slots 120. The axial width of each slot 120 is slightly greater than the overall width of leg portion 114. The length of each pin 118 is equal to the distance between housing end plates 18, 20 plus the depth of one of grooves 74, 76.

During operation, pistons 38 move radially in and out of the respective bores 34, with piston top seals 82 continuously in engagement with piston engagement surface 50. During the portion of the rotor rotation in which the top seal of a particular piston 38 engages surface portion 58, the control pin associated with the particular piston rides in groove 74 of housing end plate 16, the leg of the gate 110 of the particular piston is free to move through the slot in the control pin 118, and the gate 110 moves radially with the piston 38 and continuously overlies, and thereby closes, the opening 100 in the piston trailing wall.

During the portion of rotor rotation in which the top seal of a piston engages surface portion 60, the control pin 118 associated with the piston rides in groove 76 of housing end plate 18, and the control pin 118 engages the leg 114 of the gate 110 of the piston and holds it withdrawn into the rotor so that, as the piston moves radially outwardly, the opening 100 in the piston trailing wall 92 will be uncovered.

Motor 10 operates on a four stage cycle, and two complete revolutions of rotor 24 (counterclockwise as shown in FIG. 1) within housing 13 are required to complete any particular cycle. Two cycles are completed per revolution and, at any point of time, four different cycles are in progress.

A typical operating cycle commences when the top seal 82 of one of pistons 38, designated 38a in FIG. 1 for clarity in the following discussion, is adjacent seal 57a of piston engagement surface 50. The first stage, the intake stage, continues through approximately or rotor rotation, until top seal 82 is adjacent seal 57b. As the piston 38a moves from seal 57a to seal 57b, a gaseous air-fuel mixture from carburetor 70 is drawn through inlet conduit 63 and fills the intake and compression chamber 62 behind the moving piston 38a.

During the second stage, the compression stage, the air-fuel mixture drawn into chamber 62 by piston 38a is forced into the internal chamber 96 within the other piston, designated 38b in FlG. 1. The mixture in chamber 62 ahead of piston 38b is compressed, the pressure causes the fingers 106 of reeds 102 in piston 38b to bend, thereby opening drilled openings 98, and the entire mixture, compressed to about one-tenth its original volume, is transferred to the interior chamber 96 of the piston. When piston 38b reaches seal 57b, the reed fingers close, the pressure within the piston 38b being greater than the external pressure on the leading side of the piston, sealing the compressed mixture within piston chamber 96.

The third stage of the cycle is the combustion stage, commences as seal 82 of piston 38b passes seal 57b, and continues until the seal 82 reaches seal 57a. As the piston progresses through these approximately 200 of rotor rotation, the compressed mixture in piston chamber 96 escapes from the piston through trailing wall opening 100 into exhaust and combustion chamber 64 behind the moving piston 38b. Spark plug 72 is fired shortly after the piston passes the plug, thereby igniting the air-fuel mixture. The resulting high pressure gases expand, concommitantly causing rotation of the rotor, until seal 82 passes exhaust conduit 65.

The fourth stage of the cycle is the exhaust stage, during which piston 38a forces the expanded combustion products (of the air-fuel mixture from piston 38b) from exhaust and combustion chamber 64 through exhaust' conduit 65 and out of motor 10. Exhaust commences as soon as seal 82 of piston 38b reaches exhaust conduit 65, and continues until seal 82 of piston 38a has passed the conduit.

It should be noted that the force of gases within chambers 62, 64 against pistons 38 is always perpendicular to output shaft.

Other embodiments within the scope of the following claims will occur to those skilled in the art.

What is claimed is:

1. A rotary engine comprising:

a housing;

a rotor mounted within the housing for rotation relative thereto about an axis,

the peripheral surface of the rotor and the interior surface of the housing defining therebetween first and second chambers;

a piston carried by said rotor and movable generally radially thereof in engagement with said interior surface of said housing,

said piston including an interior chamber therein,

a first opening extending from said interior chamber through a first wall of said piston,

a second opening extending from said interior chamber through a second wall of said piston, said second wall being opposite said first wall;

first control means for permitting flow of fluid from said first chamber through said first opening into said interior chamber during one predetermined portion of said relative rotation; and,

second control means for permitting fluid flow from said interior chamber through said second opening to said second chamber during a second predetermined portion of said relative rotation,

said second control means including a closure member mounted on said piston for movement relative thereto between a first position overlying said second opening and a second position spaced from said first position and permitting said flow through said second opening, and a retainer for holding said closure member fixed with respect to said rotor during said second predetermined portion of said relative rotation and for permitting said closure member to move with said piston during said one predetermined portion of said relative rotation, said retainer comprising a pin extending through said rotor generally parallel to the axis thereof, a portion of said closure member extending through a slot in said pin, and portions of said housing engaging opposite ends of said pin and causing axial movement thereof during said relative rotation.

2. The engine of claim 1 wherein said interior surface of said housing includes a first surface portion defined by a portion of a first cylinder having an axis parallel to said axis of rotation and offset therefrom and a secondsurface portion defined by a portion of a second cylinder having an axis parallel to said axis of rotation and offset therefrom.

3. The engine of claim 2 wherein said axes of said first and second cylinders are offset on opposite sides of said axis of rotation.

4. The engine of claim 2 wherein the diameter of one of said first and second cylinders is not equal to the diameter of the other of said first and second cylinders.

5. The engine of claim 2 wherein the diameter of said first cylinder is less than the diameter of said second cylinder, the volume of said first chamber is less than the volume of said second chamber, and said axes of said first and second cylinders are offset on opposite sides of said axis of rotation.

6. The engine of claim ll wherein the volume of said interior chamber is less than one-fourth the volume of each of said first and second chambers.

7. The engine of claim 1 wherein said first control means includes a flexible closure member mounted on said piston in position for overlying said first opening and arranged for flexure away from said opening to permit said flow through said first opening.

8. The engine of claim ll, wherein said housing comprises a pair of end walls on opposite axial ends of said rotor and said portions comprise annular grooves in respective relatively. facing axial surfaces of said end walls. 7

9. The engine of claim 1 wherein said rotor defines a pair of circumferentially-spaced bores extending radially inwardly from the peripheral surface thereof and a piston is mounted within each of saidbores.

10. The engine of claim 9 wherein said bores are diametrically opposed.

11. The engine of claim 9 wherein each of said bores is rectangular in radial cross-section.

12. The engineof claim 11 wherein each of said pistons is rectangular in cross-section radial .of said rotor and includes spaced first and second walls extending parallel to said axis of rotation, and a said interior chamber intermediate said first and second walls.

13. The engine of claim 12 wherein each of said pistons includes a said first opening and a second opening.

14. The engine of claim 13 wherein said interior surface of said housing includes a first surface portion defined by a portion of a first cylinder having an axis parallel to said axis of rotation and offset therefrom, and a second surface portion defined by a portion of a second cylinder having an axis parallel to said axis of rotation and offset therefrom on the side thereof opposite said axis of. said first cylinder.

15. The engine of claim 14 wherein said first control means permits flow of fluid from said first chamber through said first opening of each respective one of said pistons into said interior chamber thereof during said one portion of said relative rotation in which said respective one piston engages said first surface portion and prevents flow of fluid from said interior chamber of said respective one piston through said first opening during a period of said relative rotation other than said one portion, and second control means permits flow from said interior chamber of said respective one piston through said second opening thereof during said second portion of said relative rotation in which said respective one piston engages said second surface portion and prevents flow of fluid through said second opening of said respective one piston during a portion of said relative rotation other than said second portion.

16. The engine of claim wherein said first control means includes a flexible reed mounted on each of said pistons inposition for overlying and closing said first opening thereof and arranged for flexure away from said first opening thereof.

17. The engine of claim 16 wherein said first opening of each of said pistons comprises a plurality of openings spaced axially of said rotor and said reed includes a other of said pair. 

1. A rotary engine comprising: a housing; a rotor mounted within the housing for rotation relative thereto about an axis, the peripheral surface of the rotor and the interior surface of the housing defining therebetween first and second chambers; a piston carried by said rotor and movable generally radially thereof in engagement with said interior surface of said housing, said piston including an interior chamber therein, a first opening extending from said interior chamber through a first wall of said piston, a second opening extending from said interior chamber through a second wall of said piston, said second wall being opposite said first wall; first control means for permitting flow of fluid from said first chamber through said first opening into said interior chamber during one predetermined portion of said relative rotation; and, second control means for permitting fluid flow from said interior chamber through said second opening to said second chamber during a second predetermined portion of said relative rotation, said second control means including a closure member mounted on said piston for movement relative thereto between a first position overlying said second opening and a second position spaced from said first position and permitting said flow through said second opening, and a retainer for holding said closure member fixed with respect to said rotor during said second predetermined portion of said relative rotation and for permitting said closure member to move with said piston during said one predetermined portion of said relative rotation, said retainer comprising a pin extending through said rotor generally parallel to the axis thereof, a portion of said closure member extending through a slot in said pin, and portions of said housing engaging opposite ends of said pin and causing axial movement thereof during said relative rotation.
 2. The engine of claim 1 wherein said interior surface of said housing includes a first surface portion defined by a portion of a first cylinder having an axis parallel to said axis of rotation and offset therefrom and a second surface portion defined by a portion of a second cylinder having an axis parallel to said axis of rotation and offset therefrom.
 3. The engine of claim 2 wherein said axes of said first and second cylinders are offset on opposite sides of said axis of rotation.
 4. The engine of claim 2 wherein the diameter of one of said first and second cylinders is not equal to the diameter of the other of said first and second cylinders.
 5. The engine of claim 2 wherein the diameter of said first cylinder is less than the diameter of said second cylinder, the volume of said first chamber is less than the volume of said second chamber, and said axes of said first and second cylinders are offset on opposite sides of said axis of rotation.
 6. The engine of claim 1 wherein the volume of said interior chamber is less than one-fourth the volume of each of said first and second chambers.
 7. The engine of claim 1 wherein said first control means includes a flexible closure member mounted on said piston in position for overlying said first opening and arranged for flexure away from said opening to permit said flow through said first opening.
 8. The engine of claim 1, wherein said housing comprises a pair of end walls on opposite axial ends of said rotor and said portions comprise annular grooves in respective relatively facing axial surfaces of said end walls.
 9. The engine of claim 1 wherein said rotor defines a pair of circumferentially-spaced bores extending radIally inwardly from the peripheral surface thereof and a piston is mounted within each of said bores.
 10. The engine of claim 9 wherein said bores are diametrically opposed.
 11. The engine of claim 9 wherein each of said bores is rectangular in radial cross-section.
 12. The engine of claim 11 wherein each of said pistons is rectangular in cross-section radial of said rotor and includes spaced first and second walls extending parallel to said axis of rotation, and a said interior chamber intermediate said first and second walls.
 13. The engine of claim 12 wherein each of said pistons includes a said first opening and a second opening.
 14. The engine of claim 13 wherein said interior surface of said housing includes a first surface portion defined by a portion of a first cylinder having an axis parallel to said axis of rotation and offset therefrom, and a second surface portion defined by a portion of a second cylinder having an axis parallel to said axis of rotation and offset therefrom on the side thereof opposite said axis of said first cylinder.
 15. The engine of claim 14 wherein said first control means permits flow of fluid from said first chamber through said first opening of each respective one of said pistons into said interior chamber thereof during said one portion of said relative rotation in which said respective one piston engages said first surface portion and prevents flow of fluid from said interior chamber of said respective one piston through said first opening during a period of said relative rotation other than said one portion, and second control means permits flow from said interior chamber of said respective one piston through said second opening thereof during said second portion of said relative rotation in which said respective one piston engages said second surface portion and prevents flow of fluid through said second opening of said respective one piston during a portion of said relative rotation other than said second portion.
 16. The engine of claim 15 wherein said first control means includes a flexible reed mounted on each of said pistons in position for overlying and closing said first opening thereof and arranged for flexure away from said first opening thereof.
 17. The engine of claim 16 wherein said first opening of each of said pistons comprises a plurality of openings spaced axially of said rotor and said reed includes a reed portion overlying each of said plurality.
 18. The engine of claim 15 wherein said first and second surface portions intersect along a pair of surface segments, each of said pair extending parallel to said axis of rotation, and including an inlet conduit extending from said first chamber adjacent one of said pair, an exhaust conduit extending from said second chamber adjacent said one of said pair, and an ignitor communicating with said second chamber adjacent the other of said pair. 